添加150. 逆波兰表达式求值javaScript版本

problems/0150.逆波兰表达式求值.md

@@ -197,6 +197,32 @@ func evalRPN(tokens []string) int {
 }
 ```
 
+javaScript:
+
+```js
+
+/**
+ * @param {string[]} tokens
+ * @return {number}
+ */
+var evalRPN = function(tokens) {
+    const s = new Map([
+        ["+", (a, b) => a * 1  + b * 1],
+        ["-", (a, b) => b - a],
+        ["*", (a, b) => b * a],
+        ["/", (a, b) => (b / a) | 0]
+    ]);
+    const stack = [];
+    for (const i of tokens) {
+        if(!s.has(i)) {
+            stack.push(i);
+            continue;
+        }
+        stack.push(s.get(i)(stack.pop(),stack.pop()))
+    }
+    return stack.pop();
+};
+```
 
 
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